Add submodule check

#13

codearchiver/modules/git.py

@@ -154,6 +154,11 @@ class Git(codearchiver.core.Module):
 		os.remove('tmp.pack')
 		os.remove('tmp.idx')
 
+		_logger.info('Checking for submodules')
+		_, commitsWithSubmodules, _ = codearchiver.subprocess.run_with_log(['git', 'log', '--format=format:%H', '--diff-filter=d', '--all', '--', '.gitmodules'], cwd = directory)
+		if commitsWithSubmodules:
+			_logger.warning('Submodules found but extraction not supported')
+
 		_logger.info(f'Removing clone')
 		shutil.rmtree(directory)